RE: High End Graphics Card for Poweredge 2950
When i needed a x8 PCIe video card for my PE T610 server, i searched far and wide but i couldn't find any appropriate cards so i research and then modify an old card XFX GF7600. This did the job. In one sense i was lucky in that i didn't have to wory about finding an appropriate driver for the graphics card as i also used a client OS, Windows 7 Ultimate, on my T610s my OS
In your case, as your system boots and you can see the boot progress on your monitor (when connected to the GT630), you may have an OS graphics driver issue or it could simply be that you have not waited long enough for the OS to load a default graphics driver.
So wait a while and let the OS do it's thing during a cold boot and hopefully it will come up. It may take 5 minutes or even (much) longer to get into the OS... and once the OS is up and running you can then install an appropriate driver for the graphics card.
Unfortunately the driver the card maker provides is almost certainly for a client OS, not a server OS. But all is not lost, depending on the server OS you are using, you could try a desktop driver meant for a client OS which is built from that same code base as used by your server OS. For example, in many cases i find Win7 drivers work with Win Server 2008R2 as they are built from the same code base.
And do consider that server OS has many 'features' turned off, notably audio and accelerated video so do look into this as it could be at the root of the issue.
As an aid to finding out what the is going on, you could revert to the embedded video and then boot into the OS. Then use msconfig.exe and on the boot tab select 'OS boot information' which will result in a scrolling display of the drivers being loaded during boot process. (You could also select the 'boot log' radio button within the boot tab of msconfig.exe which will log the boot process to a text file called %systemroot%\ntbtlog.txt). Reboot and make a mental note of the drivers, then disable the embedded video and try again noting any differences.
But as i said, i didn't have to worry about such issues. My concerns were boot times and the noise my T610 makes.
[edited to add the following]
The specs for the ASUS GT630 indicate "up to 75W no additional PCIe power required". Unfortunately this is rather cryptic statement but i assume ASUS means no (2x3 or 2x4) auxiliary power connectors are required for the card which can consume up to 75W pulled from the PCIe slot.
Do note that the PCIe slot within your server can not provide more than 25W to the card and this may be part of your issue.